Novel Kondo Behaviors Realized in the Filled Skutterudite Structure

DOI Web Site Web Site BIBCODE 被引用文献52件 参考文献175件

この論文をさがす

説明

Novel Kondo-like behaviors realized in the Pr-based filled skutterudites are reviewed based on the electronic transport properties, specific heat and de Haas–van Alphen (dHvA) experiments, along with the band structure calculations. As references, the experiments on the related La- and Ce-filled skutterudites are also studied and discussed. PrRu4Sb12 is an ordinary BCS superconductor without f-electron-derived mass enhancement. PrRu4P12 exhibits a metal–semiconductor transition at 62 K and an anomaly with a small characteristic energy at low temperatures. The Fermi surface (FS) topology is very similar between the first known heavy fermion superconductor PrOs4Sb12 and the reference compound LaOs4Sb12, suggesting the well-localized character of 4f-electrons in PrOs4Sb12. In contrast, the topology of the FS of PrFe4P12, which exhibits apparent Kondo behaviors at high temperatures and the field-induced heavy fermion state at low temperatures, is as a whole different from that of LaFe4P12, although partial similarity is visible between the two. For both PrFe4P12 and PrOs4Sb12, de Haas–van Alphen experiments revealed strongly enhanced cyclotron effective masses, in reasonable agreement with the large specific heat coefficients. The ground state is settled to be non-magnetic, and anomalous antiferro-electronic-quadrupole (orbital) ordering of Pr-ions are realized in zero field for PrFe4P12 and under magnetic fields for PrOs4Sb12, suggesting that the quadrupole degrees of freedom play key roles in the heavy-fermion and the exotic superconducting behaviors. The novel features realized in the Pr-filled skutterudites are discussed in relation with the unique crystal structures.

収録刊行物

被引用文献 (52)*注記

もっと見る

参考文献 (175)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ